LOUISVILLE – Bothered by his wearisome back once again, Tiger Woods limped and winced and grinded through what could possibly be his last round of the season.

The former world No. 1 and 14-time major champion closed with a birdie but shot his second consecutive 74 Friday at soggy Valhalla Golf Club to miss the cut in the PGA Championship. It was just the fourth time Woods, who won this championship here in 2000, missed the cut as a professional in a major.

This was Woods' 20th major since winning his last one in the 2008 U.S. Open.

"It was a long day," said Woods, who made just three birdies in the two rounds and hit many uncharacteristic shots. "I tried as hard as I could. That's about all I got. Unfortunately, just didn't play well. So consequently a pair of 74s is not very good. … The back was sore. No doubt it was sore. It went out on me on the range. I just had to play through it.

" … I couldn't make a back swing. Coming through is fine. I can't get the club back. And that throws everything off. I can't get anywhere near the positions that I'm accustomed to getting to or any of it. I can't do it."

Woods will likely not play the Wyndham Championship next week, meaning he will miss the FedExCup Playoffs that start the following week. Without playing – and being injured – Woods will have a difficult time convincing Tom Watson to use one of his three captain's picks to pick Woods for the Ryder Cup that begins Sept. 26.

The new wraparound season begins in October.

Woods played four tournaments this season, withdrawing in the final round from one, before having back surgery on March 31.

He said he felt strong enough to come back at the Quicken Loans Invitational the last week of June. While he missed the cut there, he was encouraged with his speed and power.

He then finished 69th in the British Open three weeks ago. Last week he pulled out of the final round of the World Golf Championships-Bridgestone Invitational when he injured his back when he landed in a bunker after hitting a shot from an awkward lie.

Joe LaCava, Woods' caddie, said he knew Woods wasn't right or comfortable during Friday's second round when he walked off the tee on the second hole.

"He was hurting most of the day, but not crazy," LaCava said.

LaCava had one word for the reason Woods kept on playing despite his minimalistic chances of making the cut and his obvious pain.

"Stubbornness," he said. "I asked him if he could make it worse and he said he didn't think so. When he said that, I was fine with it. I didn't fear something worse was going to happen."

Woods wasn't worried about doing further damage.

"(The injury) is not where the surgery was. It's a different area. When I fell out of that bunker last week, it's the same feeling, the same pain and same spasms," Woods said. "I need to get stronger. As I said the other day, I need to get my glutes strong again, my abs and my core back to where I used to have them. They are just not quite there yet.

" … I felt like I wasn't that far away when I came back at Quicken Loans, but you can't develop strength the same time as you are playing a lot. Obviously by playing, you can't burn the candle at both ends. I need to get stronger physically and be back to where I was."

PHOTO GALLERY: Friday at the PGA Championship

Jerry Kelly reacts on the eighth hole tee during the second round of the PGA Championship at Valhalla Golf Club. Jeff Gross Getty Images

Martin Kaymer with caddie Craig Connelly line up a putt on the 14th hole during the second round of the 2014 PGA Championship golf tournament at Valhalla Golf Club in Louisville. Brian Spurlock USA TODAY Sports

Volunteer scorer David Yeary works under a plastic tarp recording scores as rain falls in the early morning during the second round of the 2014 PGA Championship golf tournament at Valhalla Golf Club. Thomas J. Russo USA TODAY Sports

Kenny Perry, left, stands under a umbrella with his caddie Freddy Sanders on the 10th hole during the second round of the PGA Championship golf tournament at Valhalla Golf Club in Louisville. Mike Groll AP